Before Rust, most features had to be built on top of nginx, and had to carefully balance performance overhead of Lua (openresty) vs risks and maintenance costs

Before Rust, most features had to be built on top of nginx, and had to carefully balance performance overhead of Lua (openresty) vs risks and maintenance costs of C modules or patching nginx itself. The switch to Rust has been very positive overall, because it allowed Cloudflare to tackle much more ambitious projects, and own its entire stack.